Ray Zinn, the longest standing CEO of a public Silicon Valley company, stepped down from his 37-year post last week.

The 77-year-old Zinn, who co-founded the semiconductor manufacturer Micrel in 1978 as a two-man operation, has turned it into a multimillion-dollar company with a stock return exceeding 700 percent during his tenure.

Micrel — a semiconductor maker — was born when roughly 50 percent of silicon was still manufactured in the valley.